Smith A, Jauch A, Slater H, Robson L, Sandanam T
Department of Cytogenetics, Royal Alexandra Hospital for Children, Parramatta, Australia.
Am J Med Genet. 1999 May 21;84(2):125-31. doi: 10.1002/(sici)1096-8628(19990521)84:2<125::aid-ajmg8>3.0.co;2-w.
The likelihood of a paternally expressing imprinted gene in chromosome region 6(q23-24) has been highlighted by cases of transient neonatal diabetes mellitus (TNDM) in which paternal uniparental disomy (UPD) for chromosome 6 or paternal duplication 6(q23-qter) was detected. We present the case of a 38-year-old man with moderate to severe intellectual delay, short stature, small hands and feet, eye abnormality, small mouth, and obesity (without hyperphagia) beginning in mid-childhood. The perinatal and neonatal histories were normal. The patient had a duplication within 6q. Fluorescence in situ hybrisation studies were performed with single and dual hybridisations using a chromosome 6 library probe, short and long arm subregional probes, 6q23-24, 6q25.3-6qter locus-specific probes, and a 6q telomere probe. The hybridisation results defined an inverted duplication of 6q24.3 to 6q27. DNA studies with microsatellite markers from 6p and 6q showed regular biparental inheritance of chromosome 6 and confirmed that the duplication was paternal in origin. Our patient appears to be the first one known to have paternal duplication of chromosome area 6(q24-q27) who did not have TNDM as an infant. He has remained nondiabetic, although obesity, without hyperphagia, has been a constant problem since its onset in mid-childhood.
6号染色体区域（6q23 - 24）印记基因父源表达的可能性，已在短暂性新生儿糖尿病（TNDM）病例中得到凸显，在这些病例中检测到6号染色体的父源单亲二体（UPD）或6号染色体（6q23 - qter）的父源重复。我们报告了一例38岁男性病例，该患者自童年中期起出现中度至重度智力发育迟缓、身材矮小、手足短小、眼部异常、小嘴及肥胖（无食欲亢进）。围产期和新生儿病史正常。该患者6号染色体长臂存在重复。使用6号染色体文库探针、短臂和长臂亚区域探针、6q23 - 24、6q25.3 - 6qter位点特异性探针以及6号染色体端粒探针，进行了单杂交和双杂交荧光原位杂交研究。杂交结果确定为6q24.3至6q27的反向重复。使用来自6号染色体短臂和长臂的微卫星标记进行的DNA研究显示，6号染色体呈现正常的双亲遗传，并证实该重复起源于父方。我们的患者似乎是已知的首例6号染色体区域（6q24 - q27）父源重复但婴儿期未患TNDM的病例。他一直未患糖尿病，尽管自童年中期起肥胖就一直是个问题，但无食欲亢进。
